util.datamanager: Fix indexing first item if not at the very start
If the first item does not start at position 0 then the index function
produces a phantom first entry covering position zero until where the
real first item starts. When using the index, this would make it either
appear as the first item was missing or cause an off-by-one issue with
remaining items.
--- a/util/datamanager.lua Wed Jul 12 10:24:28 2023 +0200
+++ b/util/datamanager.lua Mon Jul 10 17:19:05 2023 +0200
@@ -329,7 +329,7 @@
return fh, err, errno;
end
local prev_pos = 0; -- position before reading
- local last_item_start = 0;
+ local last_item_start = nil;
if items and items[1] then
local last_item = items[#items];
@@ -340,7 +340,7 @@
for line in fh:lines() do
if line:sub(1, 4) == "item" then
- if prev_pos ~= 0 then
+ if prev_pos ~= 0 and last_item_start then
t_insert(items, { start = last_item_start; length = prev_pos - last_item_start });
end
last_item_start = prev_pos